Adding Empty Lines in Vim: Redux

A long time ago I wrote about adding empty lines in Emacs on my other blog, Emacs Redux. Now it’s time for the Vim version of this. Adding a blank line above or below the cursor is one of those tiny operations you do constantly, and Vim gives you several ways to do it – each with different trade-offs.

Normal Mode

The Obvious: o and O

Most Vim users reach for o (open line below) or O (open line above). These work, but they drop you into Insert mode. If you just want a blank line and want to stay in Normal mode, you need o<Esc> or O<Esc>.

This gets the job done, but has a couple of annoyances:

• The cursor moves to the new blank line.
• Auto-indent may leave trailing whitespace on the “blank” line.
• It pollutes the . repeat register (it records an insert operation).

On the bright side, o/O accept a count – 5o<Esc> inserts 5 blank lines below.

The Clean Way: :put

A lesser-known approach that avoids the issues above:

• :put _ – adds a blank line below the current line
• :put! _ – adds a blank line above the current line

The _ here is Vim’s black hole register, which is always empty. Since :put inserts register contents linewise, putting “nothing” results in a clean blank line. No trailing whitespace, no register pollution, and you stay in Normal mode.

:put ='' (using the expression register) works the same way, but :put _ is shorter and easier to remember.

The downside? It’s verbose to type interactively, and the cursor still moves to the new line.

The Elegant: ]<Space> and [<Space>

This is the gold standard:

• ]<Space> – adds a blank line below
• [<Space> – adds a blank line above

They also accept a count – 3]<Space> adds 3 blank lines below.

In Neovim 0.11+, these are built-in default mappings. In regular Vim, you need Tim Pope’s vim-unimpaired plugin. Note that the two implementations differ slightly – Neovim uses nvim_buf_set_lines which preserves the cursor position exactly, while vim-unimpaired uses :put with mark jumps, which keeps you on the same line but resets the column to 0.

If you’re on plain Vim without plugins, you can add equivalent mappings to your .vimrc:

nnoremap ]<Space> :call append(line('.'), '')<CR>
nnoremap [<Space> :call append(line('.') - 1, '')<CR>

The append() approach is the cleanest – no side effects on registers, marks, or undo granularity.

Insert Mode

In Insert mode your options are simpler:

• Enter – creates a new line below (or splits the line if the cursor is in the middle of text).
• Ctrl-O o – executes o as a one-shot Normal mode command, opening a line below. You end up in Insert mode on the new line.
• Ctrl-O O – same thing, but opens a line above.

Ctrl-O is handy when you want to add a line without breaking your Insert mode flow.

Comparison

Method	Stays in Normal?	Cursor Stays?	Count?	Notes
o<Esc> / O<Esc>	Yes	No	Yes	May leave trailing whitespace
:put _ / :put! _	Yes	No	No	Clean, no side effects
]<Space> / [<Space>	Yes	Neovim: yes; unimpaired: col 0	Yes	Neovim 0.11+ or vim-unimpaired
Enter	N/A (Insert)	No	No	Splits line if cursor is mid-text
Ctrl-O o / Ctrl-O O	N/A (Insert)	No	No	One-shot Normal mode

My recommendation? Use ]<Space> and [<Space>. Like most Vim users, I relied on o<Esc> and O<Esc> for years, but once I discovered vim-unimpaired (and later the equivalent built-in mappings in Neovim 0.11) I never looked back.

More broadly, I’m a huge fan of the uniform ]/[ convention that vim-unimpaired pioneered – ]q/[q for quickfix, ]b/[b for buffers, ]<Space>/[<Space> for blank lines, and so on. It’s a consistent, mnemonic system that’s easy to internalize, and I’m glad Neovim has been adopting it as built-in defaults. If you’re on Vim, do yourself a favor and install vim-unimpaired.

That’s all I have for you today. Keep hacking!